Pores for complexity

A material with the most complicated pore structure ever made is reported online this week in Nature Chemistry. The mesoporous silica has three interwoven but disconnected pore systems previous examples have been limited to two such pore systems, and are widely used as 'molecular sieves' thanks to their huge internal surface area of around a thousand square metres per gram.

Mesoporous materials -- containing pores just nanometres across -- are useful for a wide variety of applications, such as catalyst support, optics, and to separate petroleum fractions every molecule of petrol has passed through the pores of such materials.

Jackie Ying, Xiaodong Zou and colleagues designed a new templating agent around which the complex structure formed. The template molecules they used have large head-groups and long tails. The key to generating the three interwoven pore systems was finding the right ratio between the size of the head-group and how hydrophobic the tail is. The researchers suggest that the presence of both long and short channels in fibres of the material could lead to separation or controlled-release applications that offer different diffusion rates in different directions.